This logic puzzle is the numerical equivalent of a crossword. Each white cell in the diagram is to be filled with a digit from the range 1-9. The sum of each string of digits must match the “clue” given in the diagram. For example, the clue 29 above means that the four digits to its right must sum to that total. No digit may be duplicated within any entry. Can you complete the diagram?
A puzzle from the October 1962 issue of Eureka, the journal of the Cambridge University Mathematical Society:
(a) At least two of these statements, apart from this one, are true.
(b) At least two of these statements, apart from this one, are false.
(c) At least one of these statements is false.
(d) x of these statements are true.
Given that, if you knew the value of x, you could determine uniquely which statements are true and which are false, determine the value of x.
An elegant alphametic by Jonathan Joseph, from the October 1991 issue of Games magazine:
VENUS
MARS
SATURN
+ URANUS
--------
NEPTUNE
If each letter consistently represents a particular digit, what equation does this expression encipher?
Russian chess master Alexander Petrov composed this puzzle to commemorate Napoleon’s defeat in 1812:
Currently the emperor stands in Moscow, on h7. The goal is to chase him all the way back to Paris and to checkmate him there. The white knights are Cossack cavalry, and the white bishops are Russian partisans. Given these clues, which square represents Paris?
In 2007 I posted this cryptic verse by William Whewell:
U 0 a 0 but I 0 U,
O 0 no 0 but O 0 me;
O let not my 0 a 0 go,
But give 0 0 I 0 U so.
You sigh for a cipher but I sigh for you,
O sigh for no cipher, but O sigh for me;
O let not my sigh for a cipher go,
But give sigh for sigh, for I sigh for you so.
In An Almanac of Words at Play (1975), Willard R. Espy offered this addition. What does it say?
Oy OO thO he O
2 On an OO. OO bO
An OO but he never thO
He’d O the OO dealer O
For the OO OO bO.
Say, has OO’s OO brO
OO O that OO sO?
OO’s OO’s good for nO.
A puzzle by A. Savin, from the July-August 1996 issue of Quantum:
A mother, her brother, her daughter, and her son take part in a family chess tournament. Two of the four are twins. At the end of the tournament, the winner and the “loser” (the player in last place) are found to be the same age, and the winner is the opposite gender to the loser’s twin. Who won the tournament?
A brainteaser from the British intelligence agency GCHQ:
Explain the following: falkun, home de guerra, kick, lavoro, moed, mosca, raccordement, schafer, stobhach, tre, zevk.
A puzzle by National Security Agency applied research mathematician Nicholas R., from the agency’s October 2016 Puzzle Periodical:
Eddie, Layne, Kurt, and Chris are locked in a heated game of CyberChance which only one of them will win. Their fans are on the edge of their seats: everyone knows that in CyberChance, things can change at any moment. One fan, who prefers Kurt or Chris, is feeling worried since there is only a 4-in-10 chance that one of them will win. An Eddie fan brags that Eddie is twice as likely as Layne to come out on top. Another Eddie fan concurs, and adds the following observation: Chris is Eddie’s main competition. He figures that, given that Chris doesn’t win, Eddie has a 4-in-7 chance of winning. A Kurt fan has been quietly standing in the corner, listening to all the other fans, and wonders: What chance does Kurt have of winning CyberChance?
You’re tiling a floor with 4×1 and 2×2 tiles when you accidentally break one. A tile of the other shape is available. Show that it’s not possible to cover the floor by rearranging the tiles.
Alexey Khanyan devised this “no-brainer” in 2008. Black is in check. His only legal response is to interpose one of his knights, which then checks White, who must capture the knight, and so on. The whole ensuing 22-ply bloodbath unfolds mechanically, always reaching the same conclusion.
Via Tim Krabbé’s chess diary. Krabbé writes, “As it is a no-brainer, I feel free not to give the moves.” See The Sure Thing.
